Where zero IF wins: 50 percent smaller PCB footprint at 1/3 the cost - Part 1

July 11, 2016 //
By Brad Brannon, Analog Devices

Zero-IF (ZIF) architecture have been around since the early days of radio. Today the ZIF architecture can be found in nearly all consumer radios whether television, cellphones or Bluetooth technology. The key reason for this wide adoption is that it has proven time and again to offer the lowest cost, lowest power and the smallest footprint solution in any radio technology.

Historically, this architecture has been withheld from applications that demand high performance. However with the demand for wireless growing around us and the rapidly congested spectra, a change is required in order to continue economically deploying radios in the infrastructure that supports our wireless needs.

Contemporary Zero-IF architectures can satisfy these needs as many of the impairments normally associated with these architectures have been resolved through a combination of process, design, partitioning and algorithms. New advances in ZIF technology challenges the current high performance radio architectures and introduces new products with breakthrough performance to enable new applications previously beyond the reach of ZIF. This article will explore the many benefits of ZIF architectures and introduce new levels of performance that they bring to radio designs.

Challenges of the Radio Engineer

The transceiver architect today (see note 1) is challenged by a growing list of demands driven by our ever increasing requirements for wireless devices and applications. This leads to the continual need to access more bandwidth. The designer has moved over the years from a single carrier radio to multi-carrier. As spectrum becomes fully occupied in one band, new bands are allocated; now there are more than 40 wireless bands that must be served. Because operators have spectrum in multiple bands and these resources must be coordinated, the trend is towards carrier aggregation; carrier aggregation leads to multi-band radios. This all leads to more radios, with higher performance, requiring better out-of-band rejection, improved emissions and dissipating less power.

While the demand for wireless is rapidly increasing, the power and space budget are not. In fact, with an ever increasing need to economize both in power and space, reducing both the carbon footprint and the physical footprint are very important. To achieve these goals, new perspectives on radio architectures and partitioning are required.